The invention is concerned with a process for the control or regulation of analog electrical machines with an electronic switch as the regulating or control element. By the expression "analog electrical machines" are understood particularly electric motors and also current sources for welding and cutting. Electronic switches in the sense of the invention are preferably thyristors, transistors, and triac.
According to the previously known processes for controlling or regulating analog machines, the switches equipped with transistors are influenced and accordingly adjusted by the impulse width, while those equipped with thyristors or triac are influenced and adjusted by the phase intersection control method.
The disadvantage of these processes is that the signal for the controls and regulation of the electronic switch are obtained from analog components, whereby the aging of the analog components affects the precision adversely. Furthermore, the cost of an analog component for the impulse width modulation or for a multiple impulse thyristor phase intersection control is high.